Buggy code:
public class RemotingExtension implements Extension { public static final String SUBSYSTEM_NAME = "remoting" ; private static final String RESOURCE_NAME = ( RemotingExtension . class . getPackage ( ) . getName ( ) ) + ".LocalDescriptions" ; static final String NODE_NAME_PROPERTY = "jboss.node.name" ; static ResourceDescriptionResolver getResourceDescriptionResolver ( final String keyPrefix ) { } private static final int MANAGEMENT_API_MAJOR_VERSION = 1 ; private static final int MANAGEMENT_API_MINOR_VERSION = 1 ; private static final int MANAGEMENT_API_MICRO_VERSION = 0 ; @ Override public void initialize ( ExtensionContext context ) { final SubsystemRegistration registration = context . registerSubsystem ( RemotingExtension . SUBSYSTEM_NAME , RemotingExtension . MANAGEMENT_API_MAJOR_VERSION , RemotingExtension . MANAGEMENT_API_MINOR_VERSION , RemotingExtension . MANAGEMENT_API_MICRO_VERSION ) ; registration . registerXMLElementWriter ( INSTANCE ) ; final ManagementResourceRegistration subsystem = registration . registerSubsystemModel ( new RemotingSubsystemRootResource ( context . getProcessType ( ) ) ) ; <START_BUG> subsystem . registerOperationHandler ( DESCRIBE , GenericSubsystemDescribeHandler . INSTANCE , GenericSubsystemDescribeHandler . INSTANCE , false , PRIVATE ) ; <END_BUG> final ManagementResourceRegistration connector = subsystem . registerSubModel ( ConnectorResource . INSTANCE ) ; connector . registerSubModel ( INSTANCE_CONNECTOR ) ; final ManagementResourceRegistration sasl = connector . registerSubModel ( SaslResource . INSTANCE ) ; sasl . registerSubModel ( SaslPolicyResource . INSTANCE ) ; sasl . registerSubModel ( INSTANCE_CONNECTOR ) ; subsystem . registerSubModel ( RemoteOutboundConnectionResourceDefinition . INSTANCE ) ; subsystem . registerSubModel ( LocalOutboundConnectionResourceDefinition . INSTANCE ) ; subsystem . registerSubModel ( GenericOutboundConnectionResourceDefinition . INSTANCE ) ; } @ Override public void initializeParsers ( ExtensionParsingContext context ) { } static final class RemotingSubsystem10Parser implements XMLStreamConstants , XMLElementReader < List < ModelNode > > , XMLElementWriter < SubsystemMarshallingContext > { private static final RemotingExtension . RemotingSubsystem10Parser INSTANCE = new RemotingExtension . RemotingSubsystem10Parser ( ) ; @ Override public void readElement ( XMLExtendedStreamReader reader , List < ModelNode > list ) throws XMLStreamException { } void parseWorkerThreadPool ( final XMLExtendedStreamReader reader , final ModelNode subsystemAdd ) throws XMLStreamException { } void parseConnector ( XMLExtendedStreamReader reader , final ModelNode address , final List < ModelNode > list ) throws XMLStreamException { } void parseSaslElement ( final XMLExtendedStreamReader reader , final ModelNode address , final List < ModelNode > list ) throws XMLStreamException { } ModelNode parsePolicyElement ( XMLExtendedStreamReader reader , final ModelNode address , final List < ModelNode > list ) throws XMLStreamException { } private void parseProperties ( XMLExtendedStreamReader reader , final ModelNode address , final List < ModelNode > list ) throws XMLStreamException { } @ Override public void writeContent ( final XMLExtendedStreamWriter writer , final SubsystemMarshallingContext context ) throws XMLStreamException { } private void writeWorkerThreadPoolIfAttributesSet ( final XMLExtendedStreamWriter writer , final ModelNode model ) throws XMLStreamException { } private void writeConnector ( final XMLExtendedStreamWriter writer , final ModelNode node , final String name ) throws XMLStreamException { } private void writeProperties ( final XMLExtendedStreamWriter writer , final ModelNode node ) throws XMLStreamException { } private void writeSasl ( final XMLExtendedStreamWriter writer , final ModelNode node ) throws XMLStreamException { } private void writePolicy ( final XMLExtendedStreamWriter writer , final ModelNode node ) throws XMLStreamException { } } }

Fix:
subsystem . registerOperationHandler ( DEFINITION , GenericSubsystemDescribeHandler . INSTANCE ) ;